Enterobacteriaceae
A family of gram-negative, facultatively anaerobic, rod-shaped bacteria that do not form endospores. Its organisms are distributed worldwide with some being saprophytes and others being plant and animal parasites. Many species are of considerable economic importance due to their pathogenic effects on agriculture and livestock.
Enterobacteriaceae Infections
Infections with bacteria of the family ENTEROBACTERIACEAE.
beta-Lactamases
Enzymes found in many bacteria which catalyze the hydrolysis of the amide bond in the beta-lactam ring. Well known antibiotics destroyed by these enzymes are penicillins and cephalosporins.
Microbial Sensitivity Tests
Any tests that demonstrate the relative efficacy of different chemotherapeutic agents against specific microorganisms (i.e., bacteria, fungi, viruses).
Anti-Bacterial Agents
Substances that reduce the growth or reproduction of BACTERIA.
beta-Lactam Resistance
Nonsusceptibility of bacteria to the action of the beta-lactam antibiotics. Mechanisms responsible for beta-lactam resistance may be degradation of antibiotics by BETA-LACTAMASES, failure of antibiotics to penetrate, or low-affinity binding of antibiotics to targets.
Enterobacter
Gram-negative gas-producing rods found in feces of humans and other animals, sewage, soil, water, and dairy products.
Serratia
A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria that occurs in the natural environment (soil, water, and plant surfaces) or as an opportunistic human pathogen.
Proteus
A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria that occurs in the intestines of humans and a wide variety of animals, as well as in manure, soil, and polluted waters. Its species are pathogenic, causing urinary tract infections and are also considered secondary invaders, causing septic lesions at other sites of the body.
Carbapenems
A group of beta-lactam antibiotics in which the sulfur atom in the thiazolidine ring of the penicillin molecule is replaced by a carbon atom. THIENAMYCINS are a subgroup of carbapenems which have a sulfur atom as the first constituent of the side chain.
Bacteriological Techniques
Techniques used in studying bacteria.
Klebsiella
A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria whose organisms arrange singly, in pairs, or short chains. This genus is commonly found in the intestinal tract and is an opportunistic pathogen that can give rise to bacteremia, pneumonia, urinary tract and several other types of human infection.
Escherichia
A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria whose organisms occur in the lower part of the intestine of warm-blooded animals. The species are either nonpathogenic or opportunistic pathogens.
Klebsiella pneumoniae
beta-Lactams
Four-membered cyclic AMIDES, best known for the PENICILLINS based on a bicyclo-thiazolidine, as well as the CEPHALOSPORINS based on a bicyclo-thiazine, and including monocyclic MONOBACTAMS. The BETA-LACTAMASES hydrolyze the beta lactam ring, accounting for BETA-LACTAM RESISTANCE of infective bacteria.
Cephalosporins
Gram-Negative Bacteria
Citrobacter
Bacteria
One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.
Escherichia coli
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
Drug Resistance, Bacterial
Drug Resistance, Multiple, Bacterial
Drug Resistance, Microbial
Salmonella
A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria that utilizes citrate as a sole carbon source. It is pathogenic for humans, causing enteric fevers, gastroenteritis, and bacteremia. Food poisoning is the most common clinical manifestation. Organisms within this genus are separated on the basis of antigenic characteristics, sugar fermentation patterns, and bacteriophage susceptibility.
Enterobacter cloacae
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria that occurs in water, sewage, soil, meat, hospital environments, and on the skin and in the intestinal tract of man and animals as a commensal.
Klebsiella Infections
Serratia marcescens
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria found in soil, water, food, and clinical specimens. It is a prominent opportunistic pathogen for hospitalized patients.
DNA, Bacterial
Deoxyribonucleic acid that makes up the genetic material of bacteria.
Gram-Negative Bacterial Infections
Infections caused by bacteria that show up as pink (negative) when treated by the gram-staining method.
Vibrionaceae
A family of gram-negative bacteria whose members predominate in the bacterial flora of PLANKTON; FISHES; and SEAWATER. Some members are important pathogens for humans and animals.
Evaluation Studies as Topic
Aztreonam
A monocyclic beta-lactam antibiotic originally isolated from Chromobacterium violaceum. It is resistant to beta-lactamases and is used in gram-negative infections, especially of the meninges, bladder, and kidneys. It may cause a superinfection with gram-positive organisms.
Ceftazidime
Semisynthetic, broad-spectrum antibacterial derived from CEPHALORIDINE and used especially for Pseudomonas and other gram-negative infections in debilitated patients.
Proteus mirabilis
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria that is frequently isolated from clinical specimens. Its most common site of infection is the urinary tract.
Klebsiella oxytoca
Shigella
A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria that ferments sugar without gas production. Its organisms are intestinal pathogens of man and other primates and cause bacillary dysentery (DYSENTERY, BACILLARY).
Cephalosporin Resistance
Non-susceptibility of an organism to the action of the cephalosporins.
Culture Media
Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.
Kluyvera
A genus of gram-negative, facultatively anaerobic bacteria in the family ENTEROBACTERIACEAE. It is found in FOOD; SOIL; and SEWAGE; and is an opportunistic pathogen of humans.
Pseudomonadaceae
A family of gram-negative bacteria usually found in soil or water and including many plant pathogens and a few animal pathogens.
Citrobacter freundii
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria found in humans and other animals including MAMMALS; BIRDS; REPTILES; and AMPHIBIANS. It has also been isolated from SOIL and WATER as well as from clinical specimens such as URINE; THROAT; SPUTUM; BLOOD; and wound swabs as an opportunistic pathogen.
Feces
Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.
Pseudomonas aeruginosa
A species of gram-negative, aerobic, rod-shaped bacteria commonly isolated from clinical specimens (wound, burn, and urinary tract infections). It is also found widely distributed in soil and water. P. aeruginosa is a major agent of nosocomial infection.
Penicillanic Acid
Thienamycins
Beta-lactam antibiotics that differ from PENICILLINS in having the thiazolidine sulfur atom replaced by carbon, the sulfur then becoming the first atom in the side chain. They are unstable chemically, but have a very broad antibacterial spectrum. Thienamycin and its more stable derivatives are proposed for use in combinations with enzyme inhibitors.
Azabicyclo Compounds
Bicyclic bridged compounds that contain a nitrogen which has three bonds. The nomenclature indicates the number of atoms in each path around the rings, such as [2.2.2] for three equal length paths. Some members are TROPANES and BETA LACTAMS.
Conjugation, Genetic
A parasexual process in BACTERIA; ALGAE; FUNGI; and ciliate EUKARYOTA for achieving exchange of chromosome material during fusion of two cells. In bacteria, this is a uni-directional transfer of genetic material; in protozoa it is a bi-directional exchange. In algae and fungi, it is a form of sexual reproduction, with the union of male and female gametes.
Quinolones
A group of derivatives of naphthyridine carboxylic acid, quinoline carboxylic acid, or NALIDIXIC ACID.
Plasmids
Imipenem
Semisynthetic thienamycin that has a wide spectrum of antibacterial activity against gram-negative and gram-positive aerobic and anaerobic bacteria, including many multiresistant strains. It is stable to beta-lactamases. Clinical studies have demonstrated high efficacy in the treatment of infections of various body systems. Its effectiveness is enhanced when it is administered in combination with CILASTATIN, a renal dipeptidase inhibitor.
Erwinia
A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria whose organisms are associated with plants as pathogens, saprophytes, or as constituents of the epiphytic flora.
Bacteria, Aerobic
Aerobic bacteria are types of microbes that require oxygen to grow and reproduce, and use it in the process of respiration to break down organic matter and produce energy, often found in environments where oxygen is readily available such as the human body's skin, mouth, and intestines.
Anti-Infective Agents
Clavulanic Acid
Clavulanic acid and its salts and esters. The acid is a suicide inhibitor of bacterial beta-lactamase enzymes from Streptomyces clavuligerus. Administered alone, it has only weak antibacterial activity against most organisms, but given in combination with other beta-lactam antibiotics it prevents antibiotic inactivation by microbial lactamase.
Bacterial Infections
Infections by bacteria, general or unspecified.
Aminoglycosides
Amikacin
A broad-spectrum antibiotic derived from KANAMYCIN. It is reno- and oto-toxic like the other aminoglycoside antibiotics.
Bacteremia
The presence of viable bacteria circulating in the blood. Fever, chills, tachycardia, and tachypnea are common acute manifestations of bacteremia. The majority of cases are seen in already hospitalized patients, most of whom have underlying diseases or procedures which render their bloodstreams susceptible to invasion.
Acinetobacter
A genus of gram-negative bacteria of the family MORAXELLACEAE, found in soil and water and of uncertain pathogenicity.
Piperacillin
Semisynthetic, broad-spectrum, AMPICILLIN derived ureidopenicillin antibiotic proposed for PSEUDOMONAS infections. It is also used in combination with other antibiotics.
Fluoroquinolones
A group of QUINOLONES with at least one fluorine atom and a piperazinyl group.
Sequence Analysis, DNA
Kanamycin
Antibiotic complex produced by Streptomyces kanamyceticus from Japanese soil. Comprises 3 components: kanamycin A, the major component, and kanamycins B and C, the minor components.
Minocycline
A TETRACYCLINE analog, having a 7-dimethylamino and lacking the 5 methyl and hydroxyl groups, which is effective against tetracycline-resistant STAPHYLOCOCCUS infections.
Gene Transfer, Horizontal
The naturally occurring transmission of genetic information between organisms, related or unrelated, circumventing parent-to-offspring transmission. Horizontal gene transfer may occur via a variety of naturally occurring processes such as GENETIC CONJUGATION; GENETIC TRANSDUCTION; and TRANSFECTION. It may result in a change of the recipient organism's genetic composition (TRANSFORMATION, GENETIC).
Disk Diffusion Antimicrobial Tests
Gentamicins
A complex of closely related aminoglycosides obtained from MICROMONOSPORA purpurea and related species. They are broad-spectrum antibiotics, but may cause ear and kidney damage. They act to inhibit PROTEIN BIOSYNTHESIS.
Integrons
Species Specificity
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
Yersinia
A genus of gram-negative, facultatively anaerobic rod- to coccobacillus-shaped bacteria that occurs in a broad spectrum of habitats.
Chromogenic Compounds
Colorless, endogenous or exogenous pigment precursors that may be transformed by biological mechanisms into colored compounds; used in biochemical assays and in diagnosis as indicators, especially in the form of enzyme substrates. Synonym: chromogens (not to be confused with pigment-synthesizing bacteria also called chromogens).
Genes, Bacterial
The functional hereditary units of BACTERIA.
Polymerase Chain Reaction
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
Agar
A complex sulfated polymer of galactose units, extracted from Gelidium cartilagineum, Gracilaria confervoides, and related red algae. It is used as a gel in the preparation of solid culture media for microorganisms, as a bulk laxative, in making emulsions, and as a supporting medium for immunodiffusion and immunoelectrophoresis.
Bacterial Typing Techniques
Procedures for identifying types and strains of bacteria. The most frequently employed typing systems are BACTERIOPHAGE TYPING and SEROTYPING as well as bacteriocin typing and biotyping.
Esculin
Esculin is a glucoside of esculetin, a coumarin derivative found in the horse chestnut tree (Aesculus hippocastanum) and some other plants, used in medical research for its anticoagulant properties and as a substrate in susceptibility testing of certain bacteria.
Fermentation
Anaerobic degradation of GLUCOSE or other organic nutrients to gain energy in the form of ATP. End products vary depending on organisms, substrates, and enzymatic pathways. Common fermentation products include ETHANOL and LACTIC ACID.
Molecular Sequence Data
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Molecular Typing
Using MOLECULAR BIOLOGY techniques, such as DNA SEQUENCE ANALYSIS; PULSED-FIELD GEL ELECTROPHORESIS; and DNA FINGERPRINTING, to identify, classify, and compare organisms and their subtypes.
Bacteria, Anaerobic
'Anaerobic Bacteria' are types of bacteria that do not require oxygen for growth and can often cause diseases in humans, including dental caries, gas gangrene, and tetanus, among others.
Electrophoresis, Gel, Pulsed-Field
Gel electrophoresis in which the direction of the electric field is changed periodically. This technique is similar to other electrophoretic methods normally used to separate double-stranded DNA molecules ranging in size up to tens of thousands of base-pairs. However, by alternating the electric field direction one is able to separate DNA molecules up to several million base-pairs in length.
Pseudomonas
A genus of gram-negative, aerobic, rod-shaped bacteria widely distributed in nature. Some species are pathogenic for humans, animals, and plants.
Cefoperazone
Semisynthetic broad-spectrum cephalosporin with a tetrazolyl moiety that is resistant to beta-lactamase. It has been proposed especially against Pseudomonas infections.
Proteus vulgaris
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria that occurs in soil, fecal matter, and sewage. It is an opportunistic pathogen and causes cystitis and pyelonephritis.
Escherichia coli Infections
Multilocus Sequence Typing
Aeromonas
A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria that occurs singly, in pairs, or in short chains. Its organisms are found in fresh water and sewage and are pathogenic to humans, frogs, and fish.
Ceftizoxime
A semisynthetic cephalosporin antibiotic which can be administered intravenously or by suppository. The drug is highly resistant to a broad spectrum of beta-lactamases and is active against a wide range of both aerobic and anaerobic gram-positive and gram-negative organisms. It has few side effects and is reported to be safe and effective in aged patients and in patients with hematologic disorders.
Ticarcillin
An antibiotic derived from penicillin similar to CARBENICILLIN in action.
Salmonella typhimurium
A serotype of Salmonella enterica that is a frequent agent of Salmonella gastroenteritis in humans. It also causes PARATYPHOID FEVER.
Carbenicillin
Urinary Tract Infections
Inflammatory responses of the epithelium of the URINARY TRACT to microbial invasions. They are often bacterial infections with associated BACTERIURIA and PYURIA.
RNA, Ribosomal, 16S
Colony Count, Microbial
Enumeration by direct count of viable, isolated bacterial, archaeal, or fungal CELLS or SPORES capable of growth on solid CULTURE MEDIA. The method is used routinely by environmental microbiologists for quantifying organisms in AIR; FOOD; and WATER; by clinicians for measuring patients' microbial load; and in antimicrobial drug testing.
Sulbactam
A beta-lactamase inhibitor with very weak antibacterial action. The compound prevents antibiotic destruction of beta-lactam antibiotics by inhibiting beta-lactamases, thus extending their spectrum activity. Combinations of sulbactam with beta-lactam antibiotics have been used successfully for the therapy of infections caused by organisms resistant to the antibiotic alone.
Hafnia alvei
The type species for the genus HAFNIA. It is distinguished from other biochemically similar bacteria by its lack of acid production on media containing sucrose. (From Bergey's Manual of Determinative Bacteriology, 9th ed)
Food Microbiology
Enterobacter aerogenes
Gram-negative, capsulated, gas-producing rods found widely in nature. Both motile and non-motile strains exist. The species is closely related to KLEBSIELLA PNEUMONIAE and is frequently associated with nosocomial infections
Lactams
Cyclic AMIDES formed from aminocarboxylic acids by the elimination of water. Lactims are the enol forms of lactams.
Monobactams
Norfloxacin
A synthetic fluoroquinolone (FLUOROQUINOLONES) with broad-spectrum antibacterial activity against most gram-negative and gram-positive bacteria. Norfloxacin inhibits bacterial DNA GYRASE.
Penicillins
A group of antibiotics that contain 6-aminopenicillanic acid with a side chain attached to the 6-amino group. The penicillin nucleus is the chief structural requirement for biological activity. The side-chain structure determines many of the antibacterial and pharmacological characteristics. (Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed, p1065)
Computers
R Factors
A class of plasmids that transfer antibiotic resistance from one bacterium to another by conjugation.
Gram-Negative Aerobic Bacteria
A large group of aerobic bacteria which show up as pink (negative) when treated by the gram-staining method. This is because the cell walls of gram-negative bacteria are low in peptidoglycan and thus have low affinity for violet stain and high affinity for the pink dye safranine.
Gastrointestinal Tract
Clavulanic Acids
Acids, salts, and derivatives of clavulanic acid (C8H9O5N). They consist of those beta-lactam compounds that differ from penicillin in having the sulfur of the thiazolidine ring replaced by an oxygen. They have limited antibacterial action, but block bacterial beta-lactamase irreversibly, so that similar antibiotics are not broken down by the bacterial enzymes and therefore can exert their antibacterial effects.
Hospitals, University
Intraabdominal Infections
Fleroxacin
Ampicillin
Sisomicin
Antibiotic produced by Micromonospora inyoensis. It is closely related to gentamicin C1A, one of the components of the gentamicin complex (GENTAMICINS).
Naphthyridines
Naphthyridines are a class of heterocyclic organic compounds containing a naphthyridine nucleus, which is a polycyclic aromatic hydrocarbon made up of two benzene rings fused to a pyridine ring, and they have been studied for their potential pharmacological properties, including as antimicrobial, antiviral, and anticancer agents.
Cefmenoxime
A cephalosporin antibiotic that is administered intravenously or intramuscularly. It is active against most common gram-positive and gram-negative microorganisms, is a potent inhibitor of Enterobacteriaceae, and is highly resistant to hydrolysis by beta-lactamases. The drug has a high rate of efficacy in many types of infection and to date no severe side effects have been noted.
Reagent Strips
Carrier State
Central African Republic
Pyronine
Molecular Epidemiology
Trimethoprim
A pyrimidine inhibitor of dihydrofolate reductase, it is an antibacterial related to PYRIMETHAMINE. It is potentiated by SULFONAMIDES and the TRIMETHOPRIM, SULFAMETHOXAZOLE DRUG COMBINATION is the form most often used. It is sometimes used alone as an antimalarial. TRIMETHOPRIM RESISTANCE has been reported.
Reagent Kits, Diagnostic
Moxalactam
Broad- spectrum beta-lactam antibiotic similar in structure to the CEPHALOSPORINS except for the substitution of an oxaazabicyclo moiety for the thiaazabicyclo moiety of certain CEPHALOSPORINS. It has been proposed especially for the meningitides because it passes the blood-brain barrier and for anaerobic infections.
Blood
Nalidixic Acid
Staphylococcus
A genus of gram-positive, facultatively anaerobic, coccoid bacteria. Its organisms occur singly, in pairs, and in tetrads and characteristically divide in more than one plane to form irregular clusters. Natural populations of Staphylococcus are found on the skin and mucous membranes of warm-blooded animals. Some species are opportunistic pathogens of humans and animals.
Cephamycins
Naturally occurring family of beta-lactam cephalosporin-type antibiotics having a 7-methoxy group and possessing marked resistance to the action of beta-lactamases from gram-positive and gram-negative organisms.
Isoelectric Focusing
DNA Fingerprinting
A technique for identifying individuals of a species that is based on the uniqueness of their DNA sequence. Uniqueness is determined by identifying which combination of allelic variations occur in the individual at a statistically relevant number of different loci. In forensic studies, RESTRICTION FRAGMENT LENGTH POLYMORPHISM of multiple, highly polymorphic VNTR LOCI or MICROSATELLITE REPEAT loci are analyzed. The number of loci used for the profile depends on the ALLELE FREQUENCY in the population.
Cefamandole
Escherichia coli Proteins
Proteins obtained from ESCHERICHIA COLI.
Sensitivity and Specificity
Urine
Community-Acquired Infections
Any infection acquired in the community, that is, contrasted with those acquired in a health care facility (CROSS INFECTION). An infection would be classified as community-acquired if the patient had not recently been in a health care facility or been in contact with someone who had been recently in a health care facility.
Colistin
Cyclic polypeptide antibiotic from Bacillus colistinus. It is composed of Polymyxins E1 and E2 (or Colistins A, B, and C) which act as detergents on cell membranes. Colistin is less toxic than Polymyxin B, but otherwise similar; the methanesulfonate is used orally.